alternator plunger project

[edboy]

this is my lockdown brew.
one very old alternator 650 small journal crank.
damaged missmatched plunger cases
autojumble primary cover already machined.
battered a65 stator housing.
i only used a caliper for marking out and hand tools and i m quite pleased with the result.
question; would the a65 chaincase cover fit the plunger cases without modification?

[Joolstacho]

Ooorite mate... you've got me on the hook!

[edboy]

the alternator spline is very close to the triumph dimensions. i found a triumph triplex sprocket which will have to do. machine it to line up with the excellent plunger clutch. it will have to run in oil also which makes the outer cover challenging. i need an ally welder.
chain tensioner will have to be as a65
i didnt know that 3 stator bolts go inside the stator housing and bolt to the crankcases. so a little more drilling when i ve bought these studs. it would make it more secure though.
crank is on -20  so i hope it cleans up ok at the grinders. so onwards and upwards.

[berger]

edboy have you been doing that magnet canal fishing and caught a crank

[edboy]

what have you been doing with yourself now all the pubs are shut on lockdown

[berger]

canal magnet fishing treating woodworm in two garages, hoovering garages taking rrt2 out deciding to put std back in , nearly got standard back in decided to drop a tooth on gearbox and put rrt2 back in. gearbox in gearbox out, gearbox in gearbox out etc. counting teeth on cogs from a big box of cogs, losing count on cogs, swearing a lot, changing suspension on van, walking about forgetting what I am doing, putting things down and not seeing them even though they are in front of me, and trying to fit a bit of the norbsa project in, between cooking and cleaning because my bird is useless at those tasks. but I love her because she can be very funny and I like cooking. oh and helping my brother with the workshop build and errrr , waiting for the PUBS!!! to open

[muskrat]

G'day edboy.
What a great project. I'll be watching.
You could machine off the un-needed sprocket.
Cheers

[chaterlea25]

Hi Edboy and All
I'm a bit puzzled by that  crank you got?
I would have thought that by the time Alternator A10's came about they would have been large journal ??
I Would like to know the definitive answer?

John

[JulianS]

The first alternator A10 engined bikes came out late 1956 or early 1957. CA10 engines with small journal big ends. These CA10 engined bikes continued until June 1960 when the last left the factory for Lincolnshire Constabulary.

The large journal alternator engine was introduced in August 1960 at engine DA10A 101.

[edboy]

i dont know too much about triumphs, but i think the triplex  is t140 and there is a duplex sprocket that will fit nicely from the t120.
the spline is exactly the same as the alternator b31.
i m waiting for the crank to come back from the grinders before i update as i need to know what size bush i need.
i have 2 a7 alternator cranks in a lot better condition. anyone know what force they were designated to?
also, have yet to come across any alternator crankcases. whatever happened to those?

[chaterlea25]

Hi All,
Julian, thanks for the information.

I have a tank with the tapped bosses presumably for the police radio ?
It has the late teardrop badges, I have seen a few more of those tanks but have not come across an earlier style tank with the radio mounts?

Alternator crankcases and primaries seem to be really scarce !!

John

[JulianS]

There were less than 400 DA10A bikes, the  majority being exported.

Not all police bikes were alternator equipped, and with the CA10 engined bikes there does not appear to be anything in the engine number to indicate whether it was alternator equipped.

Photo from brochure dated December 1956.

[bikerboy]

Did you find an alloy welder?

[edboy]

hello bikerboy . the chaincase cover is on hold until the bottom ends rebuilt as need to know clearances.  i havent found any alloy welders i can afford yet . i m in london if any help.

[KiwiGF]

hello bikerboy . the chaincase cover is on hold until the bottom ends rebuilt as need to know clearances.  i havent found any alloy welders i can afford yet . i m in london if any help.

A mate has a s/a b33 with a triumph/a65 alternator fitted into the primary, the cush drive “dome” has been removed and replaced with a larger diameter “flat” done to accommodate the alternator, so some skilled ally welding was required.

The point of telling you this is:
A) i guess it is possible to fit an alternator to a std (single) crank, so maybe the twin crank as well.
B) the modified primary cover does not have any bolts at the front, i guess because the alternator prevents that, but the cover seals ok anyway.

I didn't take any pics of the b33’s inside case mods when I was helping my mate fix the 5 speed triumph box it also has, wish I had now as it is a potentially neat mod for my b31 rigid (which I’m pleased to say now has a bob newby belt drive  )